 /* 响应式设计 */
        @media (max-width: 992px) {
            .forum-container {
                grid-template-columns: 1fr;
            }
            
            .shell-container {
                bottom: 0;
                top: auto;
                height: auto;
                width: 100%;
            }
            
            .shell {
                width: 100%;
                height: 70px;
                border-radius: 16px 16px 0 0;
                flex-direction: row;
                overflow-x: auto;
            }
            
            .shell:hover {
                width: 100%;
                height: 70px;
            }
            
            .shell__item {
                width: auto;
                height: auto;
                flex: 1;
                min-width: 70px;
                flex-direction: column;
                padding: 10px 5px;
                margin: 5px;
            }
            
            .shell__icon {
                margin: 0;
                font-size: 20px;
            }
            
            .shell__title {
                font-size: 12px;
                opacity: 1;
                margin-top: 5px;
            }
            
            .logo, .logo-text {
                display: none;
            }
            
            .main-content {
                margin-left: 0;
                margin-bottom: 70px;
            }
            
            .top-nav {
                display: none;
            }
            
            .header {
                padding: 15px 20px;
                flex-direction: column;
                gap: 15px;
            }
            
            .auth-buttons {
                width: 100%;
                justify-content: center;
            }
            
            .search-container {
                margin-right: 0;
                width: 100%;
            }
            
            .search-box {
                width: 100%;
            }
            
            .search-box:hover .search-txt,
            .search-txt:focus {
                width: calc(100% - 60px);
            }
        }

        @media (max-width: 576px) {
            .main-content {
                padding: 15px;
            }
            
            .post-item {
                flex-direction: column;
            }
            
            .post-votes {
                flex-direction: row;
                justify-content: center;
                padding-right: 0;
                padding-bottom: 15px;
                gap: 20px;
            }
            
            .user-stats {
                flex-wrap: wrap;
                justify-content: center;
                gap: 15px;
            }
            
            .header {
                padding: 15px;
            }
        }